Wax/Trace triad: harden against empty $PSScriptRoot

Tech ran Export-FormtracepakInventory.ps1 from S:\DT\shopfloor\scripts\
waxandtrace\ and the picker fired correctly but Export-Csv failed with
'Cannot bind argument to parameter Path because it is an empty string'.
Root cause: $OutputPath defaulted to $PSScriptRoot and $PSScriptRoot came
through empty in that invocation path (suspected ISE / IEX-style host or
remote wrapper). On a [string] param, $null/empty default coerces to ''
and Join-Path then errors.

Fix in all three triad scripts: resolve a local $scriptDir via a fallback
chain ($PSScriptRoot -> $PSCommandPath -> Get-Location), and use that
instead of $PSScriptRoot for sibling lookups (Select-WaxtraceAsset.ps1,
bay-config.csv).

Export additionally:
- Drops the $OutputPath = $PSScriptRoot param default in favor of the
  same fallback chain.
- Tests / creates $OutputPath BEFORE the 90k-item registry scan so a bad
  output dir surfaces immediately instead of after a long scan.

Smoke tested on win11 VM: explicit -OutputPath '' now resolves to a
writable directory and the CSV writes successfully.

playbook/shopfloor-setup/gea-shopfloor-waxtrace/scripts/Backup-FormtracepakSettings.ps1

@@ -47,6 +47,13 @@ param(
 
 $SharedRoot = 'S:\2 WJ Scans Record Retention\backup\waxtrace'
 
+# Resolve the script's own directory robustly. $PSScriptRoot can come through
+# empty in some hosts (IEX / dot-source / certain remote wrappers), which
+# would silently skip the picker invocation below.
+$scriptDir = if ($PSScriptRoot) { $PSScriptRoot } `
+             elseif ($PSCommandPath) { Split-Path -Parent $PSCommandPath } `
+             else { (Get-Location).Path }
+
 if (-not $Destination) {
     if (-not $AssetNumber) {
         $defaultAsset = $env:COMPUTERNAME
@@ -54,8 +61,8 @@ if (-not $Destination) {
             # Prefer arrow-key picker against bay-config.csv if it is sitting
             # next to this script. Falls through to a plain Read-Host prompt
             # if no picker / no CSV available.
-            $picker = Join-Path $PSScriptRoot 'Select-WaxtraceAsset.ps1'
-            $cfg    = Join-Path $PSScriptRoot 'bay-config.csv'
+            $picker = Join-Path $scriptDir 'Select-WaxtraceAsset.ps1'
+            $cfg    = Join-Path $scriptDir 'bay-config.csv'
             if ((Test-Path -LiteralPath $picker) -and (Test-Path -LiteralPath $cfg)) {
                 $picked = & $picker -ConfigCsv $cfg -Title 'Backup FormTracePak - pick the bay being captured'
                 if ($picked) {

playbook/shopfloor-setup/gea-shopfloor-waxtrace/scripts/Export-FormtracepakInventory.ps1

@@ -27,15 +27,35 @@
 #>
 [CmdletBinding()]
 param(
-    [string]$OutputPath = $PSScriptRoot,
+    [string]$OutputPath,
     [string]$ComputerName = $env:COMPUTERNAME,
     [string]$AssetNumber
 )
 
+# $PSScriptRoot can come through empty in some PowerShell hosts (e.g. when
+# the script is invoked via IEX, dot-sourced, or run through certain remote
+# wrappers). The param default = $PSScriptRoot then coerces to '' on a [string]
+# parameter and Join-Path later fails with "Cannot bind argument to parameter
+# 'Path' because it is an empty string". Resolve $OutputPath lazily with a
+# fallback chain so the script always lands on a writable directory.
+if (-not $OutputPath) {
+    if ($PSScriptRoot) {
+        $OutputPath = $PSScriptRoot
+    } elseif ($PSCommandPath) {
+        $OutputPath = Split-Path -Parent $PSCommandPath
+    } else {
+        $OutputPath = (Get-Location).Path
+    }
+}
+
+$scriptDir = if ($PSScriptRoot) { $PSScriptRoot } `
+             elseif ($PSCommandPath) { Split-Path -Parent $PSCommandPath } `
+             else { (Get-Location).Path }
+
 if (-not $AssetNumber) {
     if ([Environment]::UserInteractive -and -not [Console]::IsInputRedirected) {
-        $picker = Join-Path $PSScriptRoot 'Select-WaxtraceAsset.ps1'
-        $cfg    = Join-Path $PSScriptRoot 'bay-config.csv'
+        $picker = Join-Path $scriptDir 'Select-WaxtraceAsset.ps1'
+        $cfg    = Join-Path $scriptDir 'bay-config.csv'
         if ((Test-Path -LiteralPath $picker) -and (Test-Path -LiteralPath $cfg)) {
             $picked = & $picker -ConfigCsv $cfg -Title 'Inventory FormTracePak - pick the bay being audited'
             if ($picked) {
@@ -128,7 +148,19 @@ $MitutoyoFileExtensions = @(
 # ----------------------------------------------------------------------
 
 $timestamp = Get-Date -Format 'yyyyMMdd_HHmmss'
-$csvFile   = Join-Path $OutputPath "formtracepak_inventory_${AssetNumber}_${ComputerName}_${timestamp}.csv"
+
+# Ensure $OutputPath exists / is creatable BEFORE doing the slow scan, so
+# the operator does not sit through a 90k-item registry walk only to have
+# the final Export-Csv fail.
+if (-not (Test-Path -LiteralPath $OutputPath)) {
+    try {
+        New-Item -ItemType Directory -Path $OutputPath -Force -ErrorAction Stop | Out-Null
+    } catch {
+        Write-Error "OutputPath '$OutputPath' does not exist and cannot be created: $_"
+        exit 1
+    }
+}
+$csvFile = Join-Path $OutputPath "formtracepak_inventory_${AssetNumber}_${ComputerName}_${timestamp}.csv"
 $inventory = [System.Collections.Generic.List[PSObject]]::new()
 
 function Add-Item {

playbook/shopfloor-setup/gea-shopfloor-waxtrace/scripts/Install-FormtracepakSettings.ps1

@@ -62,13 +62,20 @@ param(
 
 $SharedRoot = 'S:\2 WJ Scans Record Retention\backup\waxtrace'
 
+# Resolve the script's own directory robustly. $PSScriptRoot can come through
+# empty in some hosts (IEX / dot-source / certain remote wrappers), which
+# would silently skip the picker invocation below.
+$scriptDir = if ($PSScriptRoot) { $PSScriptRoot } `
+             elseif ($PSCommandPath) { Split-Path -Parent $PSCommandPath } `
+             else { (Get-Location).Path }
+
 if (-not $BackupPath) {
     if (-not $AssetNumber) {
         $defaultAsset = $env:COMPUTERNAME
         if ([Environment]::UserInteractive -and -not [Console]::IsInputRedirected) {
             # Prefer arrow-key picker against bay-config.csv if available.
-            $picker = Join-Path $PSScriptRoot 'Select-WaxtraceAsset.ps1'
-            $cfg    = Join-Path $PSScriptRoot 'bay-config.csv'
+            $picker = Join-Path $scriptDir 'Select-WaxtraceAsset.ps1'
+            $cfg    = Join-Path $scriptDir 'bay-config.csv'
             if ((Test-Path -LiteralPath $picker) -and (Test-Path -LiteralPath $cfg)) {
                 $picked = & $picker -ConfigCsv $cfg -Title 'Restore FormTracePak - pick the bay being restored'
                 if ($picked) {